<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>

<body>
<form id="myform"  method="post" action="#">
    <select name="grade" id="grade">
        <option value="1">初级</option>
        <option value="2">中级</option>
        <option value="3">高级</option>
        <option value="">未知</option>
        <option>不明确</option>
    </select>
</form>
<script>


var form = document.getElementById("myform");
var grade = form.elements["grade"];                       

grade.onchange = function(){
	console.log("被选中项目：" + this.options[this.selectedIndex].outerHTML + ", select.value = " +  this.value);
}
                

</script>
</body>
</html>
